Terminal means for toroidal electromagnetic devices



Sept. 29, 1959 R. M. MIKESELL TERMINAL MEANS FOR TOROIDAL ELECTROMAGNETIC DEVICES Filed Feb. 17, 1955 l 1 276404000 O. .0. 0 O04. QA

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INVENTOR RlcHAnn M. MmeseLL United States Patent O rvce TERMINAL MEANS EoR ToRornAL ELECTRO- MAGNEHC DEVICES Richard M. Mikesell, Indianapolis, Ind., assigner to the United States of America as represented by the Secretary of the Navy Application February 17, 1955, Serial No. 489,004

2 Claims. (Cl. 336-192) (Granted under 'Iitle 35, U.S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of `any royalties thereon or therefor.

This invention relates to toroidal electromagnetic devices and more particularly to terminal means in combination with toroidal electromagnetic devices and the method of fabricating same whereby a plurality of terminal connections may be made at desirable points of the toroidal electromagnetic device windings in a compact and in an electrically and magnetically ecient manner.

In the Well known and widely used toroidal electromagnetic devices it has been common practice to connect pigtails, or separate wire leads, at the desired points in the windings by soldering a loop of the lead around the winding wire. This lead is then extended outwardly so that it will be accessible at the exterior of the toroidal coil for connection to a terminal post o-n a conductor, as desired. These pigtails and their soldered joints cause considerable disturbance of the flux and the solder joints and leads, together with their insulation, cause lumps and partitions in the windings resulting in a heavy and bulky coil which had the pigtails and soldered joints as obstacles in the winding process. In some of the known constructions the winding wire is looped outwardly to provide a lead which is generally too fragile in many practical applications.

In the present invention a plurality of terminal leads are radially and separately imbedded in a ring of electrically non-conductive and non-magnetic material which r-ing is preferably similar in diameter to the core of the toroidal winding in which it is to be used. The terminal ring can be placed in side-by-side relation with the core and the windings wound thereon making connection to selected terminal leads, as desired. There is considerable exibility in utilizing the terminal ring in that it may be used in stacked relation to a plurality of cores, to a plurality of separate toroidal coils, or to a combination of toroidal cores Within a toroidal coil or coils. It is therefore a general object of this invention to provide a terminal means for toroidal electromagnetic devices that `are positionable within the toroidal windings with the electrical connections made within the toroid and the terminal means extending to the exterior thereby to simplify the production, to save materials, and to reduce the size of the toroidal electromagnetic devices.

These and other objects, advantages, features, and uses will become more apparent as the description proceeds when considered along with the accompanying drawing, in which:

Fig. 1 shows an enlarged top plan view of a terminal ring or washer per se;

Fig. 2 illustrates in a cross-section of an isometric View of a single toroidal coil with a terminal ring therein;

Fig. 3 illustrates a cross-sectional view of an electro- Patented Sept. 29, 1959 magnetic device of several windings, as a magnetic amplifier, with ya terminal ring therein; and

Fig. 4 illustrates the construction of a stacked electromagnetic device in cross-section with terminal rings therein.

Referring more particularly to Fig. l, a ring or washer 10 of electrically non-conductive and non-magnetic material has embedded therein in any suitable 'manner a plurality of radially extending terminal lead wires 11. While eight such terminal lead wires are shown, any number may be provided to meet the need. The terminal leads 11 preferably have insulating varnish thereon but may be covered with insulating sleeves, as shown at 12 on one of the terminal leads 11 for the purpose of example. The ring 1() may have other cross-sectional configurations, as double-concave, or the like, to meet certain -conditions of use, the ring 10 being shown in rectangular cross-section to illustrate its structure and purpose.

Referring now more particularly to Fig. 2, the terminal ring 10 is placed in juxtaposed relation with a core 14 and a Winding 15 of coil wire is wound around the ring and core between the terminal leads, or with the terminal leads sprouting through the wire strand of the winding 15. As the wire strand of the winding 15 is wound on the ring and core, connections, as at 16, are made between the wire strand and selected terminal leads by soldering the -two together at the cross-over point. The wire of the winding 15 may be in a single strand or in multiple strands as necessity requires. The winding 15 is thereby hardly disturbed in its helical path around the ring 10 and core 14 to provide a smooth winding of minimum size.

As shown in Fig. 3, the terminal ring 10 can be placed between two toroidal coil elements 20 and 21, each being wound on a core member. The coil leads may be connected by ysoldering to the selected terminal lead 11, as shown at 22. These toroidal coil elements may have a winding 23 thereover to provide an electromagnetic device as a magnetic amplifier. Leads for the coil 23 may be converted to certain selected terminal leads 11 by soldering as shown at 24.

Fig. 4 illustrates the use of the terminal rings 10 in stacked relation to a stacked toroidal electromagnetic device in which three toroidal coil elements 20, 21, and 31 are each separated by a terminal ring 10. As illustrated, an outside winding 32 is wound around the three coils 20, 21, and 31, and the two rings 10. It is to be understood that the several toroidal windings can be in any desirable combination, as coils 20 and 21 being wound by a third coil and a fourth coil over all of the coils. It is also to be understood that as many terminal rings 10 may be used, as desired or as necessity requires. That is, if more terminals 11 are needed than can conveniently be put into the two shown in Fig, 4, additional terminal rings 10 may be placed on the top of coil 20, or the bottom of coil 31, or both, and the connections made thereto as hereinbefore described for Figs. 2 and 3. The terminal lead wires 11 can be bent in any desirable direction to facilitate coupling in a circuit or mounting.

While the invention has been illustrated in use in toroidal electromagnetic devices in general it is to be understood that such devices are intended to include chokes, transformers, and magnetic couplings as well. Although the preferred forms of the invention are shown and described herein it is to be understood that many modifications and changes may be made in the constructional details and features of the invention without departing from the spirit and scope thereof and I desire to be limited only by the scope ofthe appended claims:

I claim:

1. An electromagnetic device comprising: a toroidal electromagnetic means having core means with at least one winding thereon; an electrically non-conductive, nonmagnetic, at ring-like member of uniform cross-section having isolated electrical conductors supported to extend radially outwardly from the outer periphery thereof, said flat ring1il;e member being enclosed within sa-i'd at least one winding of said 4toroidal electromagnetic means adjacent to saidA core means with the electrical conductors extending radially outwardly through said at least one Winding; and connections of said at least one 1winding to selected electrical conductors at predetermined points whereby the ux and the bulk of said electromagnetic means is substantially undisturbed.

2. An electromagnetic device comprising: a toroidal winding means on a core member, said winding means consisting of at least one winding; an electrically nonconductive, non-magnetic, one piece flat annular member of uniform cross-section of a diameter substantially equal to-that of said core member and completely enclosed within said toroidal winding means adjacent said core member, said annular member supporting a plurality of isolated, radially disposed electrical conductors extending 4 outwardly from the periphery thereof, which conductors protrude through portions of said at least one winding of said toroidal winding means and are electrically insulated therefrom to the exterior thereof; and means connecting said electrical conductors to at least one winding at predetermined points 4within said toroidal winding means whereby electrical connections to various points within the toroidal winding means is accomplished without ux disturbance.

References Cited in the le of this patent UNITED STATES PATENTS 2,194,502 Hower Mar. 26, 1940 2,290,680 Franz July 21, 1942 2,437,513 Gethmann Mar. 9, 1948 2,548,206 Drom Apr. 10, 1951 2,627,008 Dunlop Jan. 27, 1953 2,667,624 Bels Jan. 26, 1954 2,703,392 Rex Mar. l, 1955 FOREIGN PATENTS Canada Sept. 9, 1952 

